So we just bought our first house and I'm super keen in getting my neglected lawn back in shape. A lot of things I've read say don't mow til May but it's looking a little long and my neighbor who has a perfect lawn has mowed. Can I go over it with the highest setting on my mower or is it too soon? Average temperature this upcoming week is 15 celcius.

I've never heard of "mowing your lawn only between X and X" and really the height of your grass should be determined by the type of grass it is. You'll want to aerate when your lawn is deeply wet, but not muddy. However, lawn made up of cool-season grasses should be aerated in the autumn season, which has less heat stress. If your lawn is made up of warm-season grasses, do your aeration on spring or summer, when they are actively growing.

There are a lot of opinions about that question, but here is what I do in a climate roughly like yours and a lawn that gets sun 50 to 90% of the time:
1) From first cut to the end of May I cut it to a height of 5 to 6cm. That's a little higher than my neighbors, but I believe the shade from the grass prevents crabgrass seeds from sprouting.
2) From June to mid-September, I cut to a height of 7 to 8cm UNLESS WE ARE HAVING A DROUGHT. Then I cut to 10cm.
3) In the fall, I go back to 5 to 6cm and go a little lower on the last two cuts.

Quote:

Originally Posted by Guncho

How do you feel about handheld manual aerators?

I've never used one. It looks like a lot of work and hard to get a consistent aeration pattern.